Back to EveryPatent.com
United States Patent |
5,558,823
|
Gray
|
September 24, 1996
|
Method for forming walls
Abstract
A method for the production of substantially vertical walls, and
specifically, walls made of concrete, includes a single sided concrete
form used, for example, to form a concrete wall against a preexisting wall
or embankment, by pumping concrete into a gap between the form and the
preexisting wall or embankment, and raising the form vertically as the
pumped concrete settles and drys. The method enables the construction of
vertical walls of superior strength in less time as compared to currently
available systems.
Inventors:
|
Gray; Leroy D. (1760 Ferry Ave., SW., Seattle, WA 98116)
|
Appl. No.:
|
290036 |
Filed:
|
August 12, 1994 |
Current U.S. Class: |
264/33; 264/35; 264/69; 264/333 |
Intern'l Class: |
B28B 001/08; E04B 001/16 |
Field of Search: |
264/33,35,333,69,70
249/20,15,10
425/63,64,431,140,145,150
|
References Cited
U.S. Patent Documents
834253 | Oct., 1906 | Bieber.
| |
943991 | Dec., 1909 | Nelson.
| |
947160 | Jan., 1910 | Newerf.
| |
1030480 | Jun., 1912 | Packard.
| |
1122982 | Dec., 1914 | Mumford.
| |
2150830 | Mar., 1939 | Hallisy.
| |
2516318 | Jul., 1950 | Hawes.
| |
2620543 | Dec., 1952 | Scharsach | 25/131.
|
3034732 | May., 1962 | Winn, Jr.
| |
3039164 | Jun., 1962 | Kemeny et al. | 25/104.
|
3628223 | Dec., 1971 | Babee | 425/65.
|
3754066 | Aug., 1973 | Black | 264/71.
|
3991842 | Nov., 1976 | Larsen.
| |
4076778 | Feb., 1978 | Whitting | 264/33.
|
4374790 | Feb., 1983 | McGowan.
| |
4799872 | Jan., 1989 | Dowdle.
| |
4917587 | Apr., 1990 | Alpar et al. | 425/64.
|
Other References
M. K. Hurd, Formwork for Concrete, 1973, pp. 281-292, Pub.4, Amer. Concrete
Inst.
|
Primary Examiner: Aftergut; Karen
Attorney, Agent or Firm: Ward & Olivo
Parent Case Text
This is a division of application Ser. No. 08/045,418, filed Apr. 9, 1993
now abandoned and refiled as Ser. No. 08/424,551.
Claims
What I claim is:
1. A method for forming by extrusion a concrete wall having a predetermined
thickness, height, and length adjacent to a preexisting member comprising
the steps of:
(a) placing two or more substantially vertical support means at a distance
from said preexisting member, said distance representing said
predetermined thickness of said concrete wall;
(b) attaching to said support means at least one horizontally positioned
slip forming means, said slip forming means being freely movable
vertically along a height of said support means and initially resting at
or near a bottom of said support means, and said slip forming means having
a vertical dimension substantially less than its horizontal dimension and
substantially less than said predetermined height of said concrete wall;
(c) delivering a layer of concrete between said preexisting member and said
slip forming means along said predetermined length of said concrete wall
from a first end of said concrete wall to a second end of said concrete
wall,
(d) vibrating said layer of concrete along its entire length to consolidate
said concrete and mesh said concrete layer to a layer of concrete
immediately thereunder, when present,
(e) allowing said vibrated concrete to at least partially dry,
(f) raising said slip forming means upward along said support means to
extrude said concrete up against said preexisting member by pressing said
concrete against said preexisting member and to allow for pouring of a new
layer of concrete vertically above and adjacent to said partially dried
layer of concrete, and
(g) repeating steps (c) through (f) until said predetermined height for
said concrete wall is reached, thus forming said concrete wall having said
predetermined thickness, height, and length.
2. A method according to claim 1 wherein said horizontally positioned slip
forming means is a plank of wood.
3. A method according to claim 1 wherein a height of said delivered layer
of concrete is sufficient to increase said height of said concrete wall.
4. A method according to claim 3 wherein said height of said delivered
layer of concrete is insufficient to overflow said slip forming means.
5. A method according to claim 1 wherein said slip forming means is raised
by a fuel burning engine.
6. A method according to claim 1 wherein said slip forming means is raised
by an electric motor.
7. A method for forming by extrusion a concrete wall having a predetermined
thickness, height, and length comprising the steps of:
placing two or more substantially vertical support means at a distance from
a preexisting member, said distance representing said predetermined
thickness of said concrete wall;
attaching at or near a bottom of said support means at least one freely
movable slip forming means, said slip forming means having a vertical
dimension substantially less than its horizontal dimension and
substantially less than said predetermined height of said concrete wall;
depositing a layer of concrete between said forming means and said
preexisting member along said predetermined length of said concrete wall
from a first end of said concrete wall to a second end of said concrete
wall such that a space between said forming means and said preexisting
member is at least partially vertically filled with said concrete;
vibrating said layer of concrete along its entire length for consolidation
of said concrete and for integration with a layer of concrete immediately
thereunder, when present;
raising said slip forming means a sufficient amount to make room for a next
layer of concrete, but not so much as to expose a top of said previously
vibrated layer of concrete, and to thereby extrude said concrete up
against said preexisting member by pressing said concrete against said
preexisting member;
repeating said depositing, vibrating, and raising steps until said concrete
wall reaches said predetermined height thus forming said concrete wall
having said predetermined thickness, height, and length.
8. A method according to claim 7 wherein said vertical dimension of said
slip forming means is about 14 inches.
9. A method according to claim 7 wherein said concrete is deposited by
pumping means.
10. A method according to claim 7 wherein each of said layers of concrete
is four to six inches in height.
11. A method according to claim 7 wherein said slip forming means is raised
in four to six inch increments.
12. A method for forming by extrusion a substantially vertical concrete
wall having a predetermined thickness, height, and length comprising the
steps of:
setting substantially vertical support members at a distance from a
preexisting member, said distance being equal to said predetermined
thickness of said concrete wall,
connecting to said support members at least one slip forming member movable
vertically along said support members, said slip forming member having a
vertical dimension substantially less than its horizontal dimension and
substantially less than said predetermined height of said concrete wall,
pouring layers of concrete between said slip forming member and said
preexisting member at a predetermined rate, and along said predetermined
length of said concrete wall from a first end of said concrete wall to a
second end of said concrete wall,
vibrating said layers of concrete to consolidate each layer and to bond
adjoining layers of concrete,
raising said slip forming member at a predetermined rate to extrude said
concrete up against said preexisting member by pressing said concrete
against said preexisting member, and repeating said pouring, vibrating,
and raising steps until said concrete wall reaches said predetermined
height thus forming said concrete wall having said predetermined
thickness, height, and length.
13. A method according to claim 12 wherein said slip forming member has a
height of about 14 inches.
14. A method according to claim 12 wherein said concrete is deposited by
pumping means.
Description
FIELD OF THE INVENTION
The invention is related to a method and apparatus for forming
substantially vertical walls by using a single travelling forming member,
which travels along substantially vertical rails. As the single travelling
forming member travels upward, a concrete wall is extruded from concrete
pumped between a base wall and the single travelling forming member.
BACKGROUND OF THE INVENTION
In the formation of substantially vertical concrete structures, it is well
known in the art to use forms, usually made of wood, for molding concrete.
Traditionally, the wooden forms are constructed with interior dimensions
and shapes exactly equal to the concrete wall to be poured and formed
within. That is, once the poured concrete fills the form, it is left to
dry, and with the form removed, the concrete will remain in the desired
form. Such wooden forms must be constructed with substantially durable and
heavy gauge plywood, so that the intense pressure (due to the heavy weight
of concrete) pent-up within the form is contained. Such wooden forms are
routinely constructed at great expense, and require a great deal of skill
to set up and disassemble once the concrete is dry. Furthermore, upon
disassembling the forms, it is common that parts of the interior hardened
concrete can become damaged if the form is not carefully and properly
removed.
Many other shortcomings exist with the use of traditional forms that are
assembled like boxes. "Box" forms must be constructed with all sides in
place, thus leading to relatively high material costs for constructing
forms generally. Also, because overall construction costs are generally
driven by time constraints, the additional time required for assembling,
placing and disassembling box forms results in substantial costs and
diminished productivity.
When relatively high and narrow concrete structures are formed with
correspondingly high and narrow box forms (for example, a ten foot (10')
high by four inch (4") wide wall), other problems can result from the lack
of access to the area in which the concrete is being poured. For example,
if in the case of pouring a 10' high by 4" wide wall, a cement mixer
fails, pouring must be halted. This can happen even though the wall
formation may only be barely underway. In this event, although iron
support rods or rebar will provide support between the wall segments which
were poured at separate times, it is desirable to install a water barrier
between the two wall segments. For this purpose, water barriers or "water
stops" are often partially placed into the upper most surface of the
recently poured, wet concrete. Then, when pouring is recommenced, the
protruding portion of the water stop protrudes into the next segment of
the concrete wall that is being poured. Such water barriers are often made
of rubber or some type of polymer, and are generally desirable whenever an
unexpected "cold joint" occurs. Unexpected cold joints are common in the
practice of pouring concrete walls, but the insertion of water barriers is
often not possible. For example, in the case of deep and narrow box forms,
it is often impossible to have access to the uppermost surface of the
freshly poured concrete, as it could be several feet down into the form.
Thus, box forms have many shortcomings.
One way to avoid the use of box forms is through the use of "slip-type"
forms, as described by M. K. Hurd, Formwork For Concrete, published by the
American Concrete Institute in 1973. In the article, a special technique
for concrete construction is set forth, using a slip form. The major
advantages of such slip forms are speed and cost. With respect to slip
forms used to create substantially vertical walls, two opposing forms
traditionally travel along the vertical length of rails to form a vertical
concrete wall between the two forms. The two opposing forms travel
continuously upward as the concrete is inserted between them. This type of
slip form, that is, the two-sided slip form, can only be used where few
projectiles traverse the sliding direction, if not, one of the two sliding
members could become impacted against the protruding projectiles.
Another problem with traditional two-sided slip forms entails the cost of
constructing two separate form-slider mechanisms. That is, two redundant
forms each associated with sets of rails must be constructed, one form and
set of rails for each side of a wall to be formed. Also, where an
embankment or wall is already existent (that is, a so-called "base wall"
exists), it is most desirable to form concrete walls against such base
walls. That is, when a two-sided form is used to construct a vertical
wall, the newly formed wall must necessarily be bolted or otherwise
fastened to the previously existent base wall. Such bolts require that
holes be drilled through both adjacent walls, so they can be fastened
together. The bolt holes can lead to water or thermal leakage. Also, over
periods of time, such bolts can become corroded, thus affecting the
structural integrity of the overall wall. By forming a concrete wall
against a base wall, the two walls, in effect, would become fused
together, since the wall being formed drys as it is pressed up against the
base wall, leading to a sealed (air and water tight) unit when the poured
wall dries. If a two-sided slip form is used, such an arrangement is
impossible, since one side of the two-sided form will always be present
between the existent walls or embankments (base walls) and the newly
formed wall.
Another problem with two-sided slip forms is that the two forms must be
positioned opposed to each other, and able to withstand intense pressure,
resulting in higher construction costs.
Finally, with respect to positioning concrete against existent or base
walls, care must be taken not to cause loose dirt or gravel to slide into
the concrete mix. That is, if the ground above the drop-off of an
embankment is disturbed, loose dirt or gravel may enter the area where the
concrete is to be formed, causing impurities to enter the concrete wall.
For example, if a cement mixer is positioned immediately above a gravel
embankment, there could be a tendency to cause loose gravel to fall into
the area below where the concrete is to be poured and formed. Although a
two-sided form can help prevent this occurrence (one side of that type of
form lies between the forming area and the embankment), constructing a
one-sided forming system would be especially susceptible to gravel
contamination, where concrete is placed into the forming area directly by
a concrete truck or workers by shovel who are positioned at the rim of the
embankment.
Other problems exist in construction with traditional concrete wall forming
techniques. Slip forms, for example, are often over sized to accommodate a
maximum amount of concrete at any given instant in time. This often leads
to protracted setting and drying times. Also, when concrete is manually
shoveled into a form, it is often first dropped (often from a shovel and
wheel-barrow) onto a sheet of plywood adjacent to the opening in a wooden
form, before ultimately being shoveled into the concrete forming area
within the form. Problems have been experienced in this regard, however,
because the cement and water often separate from the gravel (or rocks),
thus sacrificing concrete strength and quality. This is often the case,
even where traditional slip-forming is used, because slow concrete
delivery systems (e.g., by hand) cannot keep up with the forming process.
Overpouring into the slip forms, also problematic, results in not being
able to move the slip form upward in time before the freshly poured
concrete begins to adhere to the form. Generally, the more concrete that
is poured against the forms, the more difficult it is to move the forms,
due to frictional forces.
SUMMARY OF THE INVENTION
The present invention drastically improves conventional sliding form
construction. First, slip forms, traditionally consisting of two opposing
form sides, are constructed with but a single traveling form, or a
"one-sided" slip form. The one-sided horizontally positioned slip form is
disposed across at least two substantially vertically positioned support
beams, which are firmly anchored in place into or upon the ground, with
the help of lateral supports well known in the art if desired. The
one-sided slip form initially rests near the ground, and forms a gap
between it and an adjacent "base wall". That is, wet concrete is
introduced between the one-sided slip form and an existent base wall
(which may be a pre-existent wall, gravel or sand embankment, etc.). Then,
as the concrete is introduced into the gap between the form and base wall
(the area where the concrete wall is being formed), the one-sided slip
form is moved upward. The upward (vertical or substantially vertical)
movement can be performed continuously, periodically, randomly, in steps,
or in any other manner desired, so that a concrete wall is extruded, or
left in the wake of the one-sided slip form. Optimally, the vertical
height of the one-sided slip form is minimal, as greater height result in
greater form to wet concrete wall surface areas, which creates more
friction and makes the extrusion process more difficult as the one-sided
form is moved upward. For example, if a thirty (30) foot high wall is to
be constructed, and the wall is to be 120 feet in length, a one-sided form
fourteen inches (14") in height is sufficient. In constructing such a
wall, the one-sided slip forms (depending on the length of each form, a
number of forms placed end to end next to each other, each with its own
set of vertical support posts, are required to construct a 120 foot wall)
are initially positioned near or at the ground level (for example, twelve
10 foot long forms can be placed next to each other to yield a 120' wall).
About 4" of concrete is placed into the gap between the one-sided slip
form and the base wall, and the one-sided slip form is then moved upward
about 4" at a time, as concrete is laid out in a bead from one end of the
120 foot wall to the opposite end. Because of the problems associated with
positioning cement trucks or concrete mixers immediately adjacent to the
area where the concrete wall is to be formed (for example, a concrete
mixer or truck may cause loose gravel to fall over the rim of a gravel
embankment into the forming area, resulting in impurities within the
formed concrete wall), and because the rate of concrete delivery must be
controllable with respect to the raising of the form, a concrete pumping
system or otherwise mechanized concrete delivery system must be utilized
according to the present invention. When the concrete has been laid out
(with the use of concrete pumped through a hose) along the entire length
of the one-sided slip form, the form is continuously moved upward in 4"
increments until the wall is, for example, 30 feet high. In effect, the
one-sided form performs an extrusion process, by pressing the freshly
poured concrete against the base wall. By exposing 4" of the poured
concrete to the air at a time, the concrete settles and dries at rates not
attainable by the prior art. For example, according to the present
invention, 30" of wall can be poured in about an hour. Of course, other
variables can be adjusted to optimize the process described above, for
example, using hot water to mix the concrete in colder temperatures,
adjusting the coarseness of the gravel used in the concrete, the cement to
water ratio, etc.
The present invention leads to markedly more efficient and effective
concrete wall construction, since only a single form mechanism need be
assembled. Also, since the vertical height of the single sliding form is
always small in comparison to the height of the wall to be constructed,
construction costs are reduced, as less wood is required and no plywood is
required at all. The only form required can be, for example, a 3" by 14"
by 80" plank of wood. The prior art typically used forms of at least 30"
in height. By using forms with so much surface area in common with freshly
poured wet concrete, friction complicates the wall formation process
because of the tremendous friction between the sliding form and the wet
concrete. Also, a great deal more force is required just to set the slip
form into upward motion, all but ruling out the use of non-mechanized
devices to raise the forms of course, by eliminating one side of the
conventional two-sided form entirely, the effects of friction are already
reduced by the present invention, but also, the minimal height of the
sliding form of the present invention is tremendously advantageous.
The present invention uses substantially narrower forms, and in turn, the
form is moved vertically upward quicker (and in a greater number of steps)
than is conventionally used in the prior art. By adding extra vertical
steps in the formation of concrete walls, greater concrete strength for
the overall wall is achieved, since each individual layer of poured
concrete is thinner and the concrete drys quicker and with greater
strength, and the individually poured layers mate better with each other.
That is, a more homogeneous concrete mixture is obtained, drying to form a
stronger and more durable concrete wall. To facilitate the settling
process (so that the individually poured layers mate well with each
other), a so-called "pencil vibrator" is drawn through each of the newly
deposited layers after they are poured, so each layer immediately bonds to
the layer beneath it, and any air pockets contained within the concrete
are eliminated.
Because each concrete layer is deposited into such a shallow gap, and
because the form is moved upward so quickly, the present invention
required the use of a mechanized concrete delivery system, such as
concrete pumped through a hose that can be drawn through the entire length
of the gap between the one-sided slip form and the base wall. The present
invention also relies somewhat on the use of a constant volume output
concrete pumping mechanism to deliver relatively thin layers of concrete,
one layer at a time, to the gap between the one-sided slip form and the
base wall. The concrete should optimally be delivered via a hose which
fits within the gap between the form and the base wall. The deposited
layers of concrete may, for example, be on the order of 4" in depth, and
have a width equal to the gap between the form and the base wall. Each
layer is poured across the entire length of the concrete form. By using a
concrete pump, the concrete may be poured in uniformly thick layers and at
a rate substantially fast enough so that the one-sided slip form can be
lifted upward (leaving a concrete wall in its wake) at drastically higher
rates.
Other aspects of concrete wall forming can be modified to facilitate the
use of the present invention with superior results. Typically, iron rods
(or rebar) are placed within the concrete wall close to its interface with
the slip-form, thus adding to the overall strength of the concrete wall.
Also, because concrete must be pumped layer by layer into the gap behind
the one-sided form, it is crucial that the mixture of cement and gravel be
adjusted accordingly. For example, whereas traditionally, 4.5 to 5.5
100-pound bags of cement are used per cubic yard or "yard" of concrete
required, 6 bags of cement are used, to "richen" the mix, or decrease the
amount of water in each yard of concrete. Because the height of the form
is minimized according to the present invention, too much water could
impede the wall extrusion rate. Also, finer gravel, on the order of 1/4"
in diameter or so called "pea gravel", instead of the traditional. 3/4"
diameter gravel is preferably used according to the present invention. By
changing the consistency of the concrete, it can be pumped at a rate that
allows the one-sided slip form to be used with maximum efficiency. Of
course, additives, such as DURASET, a setting accelerator can be used to
hasten the setting of the concrete. As the exterior of the newly poured
concrete wall is exposed when the one-sided form is raised (for example,
at 4" at a time), the concrete exposed to air (4" at a time) immediately
forms a sort of "crust" around the surface of the extruded concrete wall.
This crust serves to hold back the wet concrete still contained within the
interior of the freshly poured wall, to maintain the shape of the
substantially vertical wall. By substantially vertical, it is intended
that the present invention be primarily used to construct walls that are
perpendicular or nearly perpendicular to the ground.
By following the description of the invention set forth above, concrete
walls of superior strength can be constructed in drastically reduced
times. Test results have shown that traditional concrete walls can support
4,000 lbs. per square inch (PSI), whereas a concrete wall made with the
present invention can often withstand pressures of 6,000 PSI. And in
addition, this enhanced strength is accomplished in less time than with
the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall diagram of the present invention which, from left to
right, shows the construction (or extrusion) of a vertical concrete wall
by three separate forms placed end to end according to the present
invention.
FIG. 2 is a detailed diagram of the initial set-up of the present invention
to form a concrete wall.
FIG. 3 is a identical to FIG. 2, except that the concrete wall has nearly
been completed.
FIG. 4 is a top view of a wall corner formed by the present invention.
FIG. 5 is a top view which shows an interior wall supported by a wall
formed by the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an overall view of a concrete wall 50 being poured via hose
52, at three positions or segments from left to right, labelled 12, 20 and
30 respectively. That is, to construct a wall 50 of any desired length, a
number of forms 14 may be placed next to each other, end to end, to obtain
the desired length. As shown, the three wall segments 12, 20 and 30 are
being added to concrete wall 57, which ,was previously poured and formed
to its full height. At segment 12, the one-sided form 14 is shown nearest
the ground 16. Hose 52 is moved from one end of the single sided slip-form
14 to the other so that a layer of concrete 50 is deposited behind it.
That is, the concrete 50 is deposited into the gap 62 (shown in FIG. 2)
between base wall 18 and form 14. At segment 20, the form 14 has been
raised by cables 22 to a height equal to approximately 1/2 of the wall to
be constructed. Winches 24 are used to raise the one-sided slip form 14
vertically upward as more concrete 50 is pumped through hose 52 and into
gap 62. Optimally, form 14 is raised as quickly as possible, leaving
behind a wall in its wake. This can be characterized as a concrete
extrusion process, with form 14 serving to extrude the concrete up along
the base wall 18. Cables 22 are attached to support posts 26, which are
supported by footing 28 (shown in FIG. 2). Support posts 26 may also be
fastened at their top ends to the base wall 18 and at their bottoms to the
footing 28 by lateral supports well known in the art (not shown). At
segment 30, the concrete wall 50 is shown to be nearly completed. At that
point, the slip form 14 has been vertically raised to its maximum height
by winches 24 along cables 22. In the case where the wall segments 12, 20
and 30 start out (at their bottoms) at unequal levels (for example, the
footing 28 is a series of tiers or steps), the forms 14 for each
respective segment 12, 20 and 30 will each commence being raised at
different times, in the order where the lowest level wall segment form 14
starts upward first, until it reaches the height of the second highest
form 14, and so on, until all three forms 14 (at segments 12, 20 and 30)
can be raised together to the same final height.
In FIG. 2, the concrete wall 50 at segment 12 of FIG. 1 is shown. The form
14 and associated hardware are shown in greater detail to illustrate the
forming system of the present invention. The concrete forming system of
the present invention functions to produce concrete walls 50 of superior
strength and in drastically reduced production times. Upon and/or within
the ground 16, a footing 28 is prepared to support post supports 26. The
support posts 26 can be 6" by 6" high pressure wooden timbers, capable of
remarkable strength and sufficient in length to allow a concrete wall 50
of any desired height to be constructed. That is, the supports 26 must be
at least as high as the desired height of the wall 50 to be constructed,
and preferably should not exceed the height of the available base wall 18.
If the supports 26 exceed the length of the base wall 18, stops (not
shown) should be placed on the supports 26 to stop form 14 before it can
be raised above the height of the base wall 18. If not, the form 14 may be
left to sway out of the vertical plane. Attached to the support posts 26
are cables 22 which are fastened to the supports 26 by way of cable
attachment hooks 38. Cables 22 are connected to winches 24, which can be
common "come along" winches with handles 25, so that the form 14 can be
raised by activating the winches 24. Of course, any manual or mechanized
transit device, such as a motor, linear actuator, screw jack, or the like,
can be used instead of winches 24. With the present invention, the form 14
can be raised in 4" increments by activating winches 24. Form 14 can
consist of a 3" by 14" plank of wood, sufficient in length to construct a
concrete wall 50 of desired width. Form 14 should possess sufficient
tensile strength to contain wet concrete 50 within gap 62, although the
relatively minimal height of form 14 (for example, about 14") minimizes
the amount of wet concrete that must be contained at any given instant in
time, and in turn, minimizes the strength required by form 14 to hold the
poured concrete 50. The thickness of the concrete wall 50 is established
by setting the gap 62 between the form 14 and the base wall 18. Because
the present invention uses a single form 14 (a one-sided form) for
constructing walls 50, the wall 50 is pressed and formed up against base
wall 18, which may be a dirt or gravel wall, tunnel lagging, embankment or
any other vertical or substantially vertical structure, wall or surface.
Thus, a major shortcoming of the prior art is overcome because there is no
need to construct one concrete wall and bolt it to another--the present
invention allows the formation of a concrete wall 50 directly against an
existent base wall 18, which can be any preexistent substantially vertical
structure. The technique of the present invention also helps prevent water
leakage that can result from driving bolts through two adjacent concrete
walls--whereby water can seep through the bolt holes.
Rebar or other reinforcing member 40 is placed within the poured concrete
wall 50 and is ideally located closer to the form 14 than to the base wall
18. In this manner, the strength of the resulting concrete wall 50 is
enhanced.
It is preferable to lay the wet concrete 50 down into gap 62 in layers
along the length of form 14. The thickness of these layers should be less
than 1/2 of the height of the form 14. Although traditional forms 14 have
often had a height of nearly 3' or more, the form 14 of the present
invention has a significantly reduced height, for example, on the order of
14". In this preferred embodiment, the wet concrete 50 is deposited by
hose 52 in 4" layers, across the length of form 14, from one end to the
other. As the wet concrete 50 is deposited in these layers, the form 14 is
raised in 4" increments by activating winches 24. Then, more wet concrete
50 is poured to fill the gap 62 and the form 14 is raised again, leaving a
concrete wall 50 in its wake.
Form 14 cannot be raised too quickly or else the wet concrete 50 will not
have had a sufficient time to dry and the concrete wall 50 will slide out
from under the form 14. In order to solve this problem and to increase the
strength of the concrete wall 50 while reducing the setting time, wet
concrete 50 can be modified to facilitate the present invention.
Traditionally, wet concrete 50 consists of 3/4" diameter gravel, water and
4.5 to 5.5 100-pound bags of cement. It is critical that enough water be
used to allow the wet concrete 50 to travel through the hose 52, however,
if too much water is used, the resulting concrete wall 50 may never
possess the necessary strength. Therefore, according to the present
invention, around six (6) 100-pound bags of cement can be used per yard
(cubic yard) of wet concrete 50 required. Also, instead of using 3/4"
diameter gravel, 1/4" diameter gravel or "pea gravel" can be used to
facilitate the flow of wet concrete 50 through hose 52.
A pencil vibrator (not shown in the figures), well known in the art, is
used to vibrate each layer of wet concrete 50 as the concrete is
deposited. The pencil vibrator is dragged along the length of the layer of
wet concrete 50, and as concrete is deposited by hose 52 along the length
of the gap 62 behind the form 14, the vibrator follows behind the hose 52
to promote mating between the poured concrete layers to each other and to
eliminate air pockets that may exist. All of the foregoing steps promote
the formation of stronger concrete walls 50.
In FIG. 3, which is identical to FIG. 2, a nearly completed concrete wall
50 is shown, as illustrated in FIG. 1 at position 30. The form 14 has been
raised to near the top of post supports 26, leaving behind a concrete wall
50 in its wake. In effect, the form 14 extrudes concrete wall 50 upward
along base wall 18.
FIG. 4 is a top view of a wall corner as formed by the present invention.
Two forms 14 are positioned to form a right angle between them, although
the forms 14 can be positioned at any angle with respect to each other
desired. Vertically positioned support posts 26 support forms 14 by way of
cables and supporting hardware 22, so that the forms 14 can be raised from
the bottom to the top of a wall 50 to be formed. Wall 50, typically made
of concrete (although any other formable material can be used), is poured
and both forms 14 are raised until both walls 50 (that is, each wall 50 at
a right angle to the other) are formed or extruded to the desired height.
When the walls 50 have dried, the resulting wall is as shown in FIG. 4,
whereby the walls 50 dry to form a right angle. Rebar 40 (or internal
supporting member 40, which may be of any suitable material) is imbedded
within walls 50 to provide support, and extra supporting members or rebar
41 can be placed at the corner of the wall 50 to provide necessary
strength.
FIG. 5 is a top view of the present invention which shows an internal wall
64 held in place by concrete wall 50 formed according to the present
invention. Supplemental support rods or rebar 62, held in place by
concrete wall 50 and other support rods or rebar 40, mate with interior
wall 64 to hold it in place. Vertically positioned support posts 26 and
cables (and associated mounting hardware) 22 enable forms 14 to be raised
to form walls 50 on each side of the supplemental support rods 62. As the
formed walls 50 (one portion of the wall 50 formed by each form 14) are
extruded by forms 14, the two wall 50 portions are fused together around
the supplemental support member 62, which is then permanently held in
place when the concrete 50 settles and dries.
Naturally, the invention is not limited to the above described examples of
the process or to the illustrated and explained embodiments of the
apparatus. Alternatives to the apparatus and method described herein would
be immediately apparent to those of skill in the art. Such alternatives
are intended to be included within the scope defined by the claims.
Top